<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div th:text="${ok}"></div>
<form action="/tmp" method="post" enctype="multipart/form-data">
<input name="file" type="file"/>
   <button type="submit">上传</button>
</form>
</body>
</html>